On the left bank of the Rhine you can climb up to a terrace on the Alter Zoll, which was a bastion in the city’s fortifications.
At this height there’s a fine view of the Rhine, and the cannons are a reminder of the structure’s former defensive purpose.
In the distance to the southeast you can make out the Siebengebirge, a range of volcanic hills.
There’s also a lot of public art and monuments around the bastion, like the statue for the writer Ernst Moritz Arndt and an abstract memorial for the Romantic poet Heinrich Heine by Ulrich Rückriem.